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From |
"Nadeem Shafique" <nadeemshafique@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: RE: Adding Matrices generated from a loop |

Date |
Mon, 27 Aug 2007 18:10:41 +0500 |

Respected Nick Cox, Thank you so much, only with your though provoking ideas I am able to complete my task. May God increase your knowledge. Best Regards, Nadeem On 8/24/07, Nick Cox <n.j.cox@durham.ac.uk> wrote: > Perhaps I should add that initialising the sum matrix > to be zeros can be best. Initialising the sum matrix > to be the first matrix is not, of course, the only > way to do it. > > Nick > n.j.cox@durham.ac.uk > > Nick Cox > > > Well, initialise outside the loop, and add each replaced > > t_i to the sum so far each time round the loop. Naturally, > > all the matrices must be conformable. > > > > Nick > > n.j.cox@durham.ac.uk > > > > Nadeem Shafique > > > > > Sorry for not providing complete information, I am trying it using > > > Mata. Following is the code i am trying to execute. > > > > > > ************************************************************** > > > ****************************** > > > for (i=1; i<=rows(info); i++) > > > { > > > > > v_i = > > > panelsubmatrix(v, i, info) > > > m_i = panelsubmatrix(m,i,info) > > > n_i = panelsubmatrix(s,i,info) > > > n = mean(n_i) > > > t_i=v_i*m_i*n > > > > > > } > > > > > > ****************** I want to sum all these t_i in one matrix say "t" > > > > > > > On 8/24/07, Nick Cox <n.j.cox@durham.ac.uk> wrote: > > > > There may be subtleties here I am missing, but > > > > I would initialise > > > > > > > > sum <- first_matrix > > > > > > > > and then loop over the other matrices > > > > > > > > sum <- sum + next_matrix > > > > > > > > This is pseudocode. > > > > > > > > Otherwise I can't tell what's troubling you about > > > > this. As the details will depend on whether > > > > you are using Stata or Mata, your naming structure, > > > > what else you are doing with these matrices, > > > > whether the number is predictable in advance, etc., > > > > none of which is indicated, I'll leave it there. > > > > > > Nadeem Shafique > > > > > > > > > I want to add several matrices (say K) of the same order, > > > suppose the > > > > > matrices to be added are comming from a loop, how can i > > > calculate the > > > > > following > > > > > > > > > > K > > > > > Sum X_i > > > > > i=1 > > > > > where X_i is the ith Matix > > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > -- Nadeem Shafique Butt * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**RE: st: RE: Adding Matrices generated from a loop***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**RE: st: RE: Adding Matrices generated from a loop***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

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